Microscopy system for eye surgery and method of illumination

Abstract

A microscopy system for eye surgery with an objective lens is suggested, which provides a retroillumination system to generate a so-called red reflex illumination during an eye-surgical treatment, in particular during a cataract operation.

What is claimed is: 
     
       1. A microscopy system for eye surgery, the microscopy system comprising:
 an objective lens for imaging an object plane of the objective lens; 
 a retroillumination system for generating at least one beam of retroillumination light directed towards the object plane from an objective lens side of the object plane wherein said beam of retroillumination light comprises substantially only visible light having wavelengths greater than 540 nanometers; and 
 a standard illumination system for generating a standard illumination beam directed towards the object plane from the objective lens side of the object plane, wherein an angle between a main ray of the beam of retroillumination light and a main ray of the beam of standard illumination light is greater than 3°. 
 
     
     
       2. The microscopy system according to  claim 1 , wherein the beam of retroillumination light comprises substantially only visible light having wavelengths greater than 600 nanometers. 
     
     
       3. The microscopy system according to  claim 1 , wherein the beam of retroillumination light comprises red light. 
     
     
       4. The microscopy system according to  claim 1 , wherein the retroillumination system comprises a filter in a beam path of the beam of retroillumination light, wherein the filter is configured to be non-transparent for light other than red light. 
     
     
       5. The microscopy system according to  claim 1 , wherein the retroillumination system comprises a mirror in a beam path of the beam of retroillumination light, wherein the mirror is configured to reflect substantially only red light. 
     
     
       6. The microscopy system according to  claim 1 , wherein the retroillumination system comprises a light source emitting substantially only red light. 
     
     
       7. The microscopy system according to  claim 6 , wherein the light source comprises at least one of a light emitting diode and a semiconductor laser. 
     
     
       8. The microscopy system according to  claim 1 , wherein the retroillumination system comprises a light source for generating a light beam and a beam splitter for splitting the light beam into a beam of standard illumination light and the beam of retroillumination light such that the beam of standard illumination light is directed towards the object plane from the objective lens side of the object plane. 
     
     
       9. The microscopy system according to  claim 1 , wherein the main ray of the beam of retroillumination light traverses the object plane under an angle of about 0° to about 40° with respect to an optical axis of the objective lens. 
     
     
       10. The microscopy system according to  claim 1 , wherein the main ray of the beam of retroillumination light traverses the object plane under an angle of about 1° to about 3° with respect to an optical axis of the objective lens. 
     
     
       11. The microscopy system of  claim 1 , wherein the main ray of the standard illumination beam traverses the object plane under an angle greater than 6° with respect to the optical axis of the objective lens. 
     
     
       12. The microscopy system according to  claim 1 , wherein the retroillumination system comprises a light source and a plurality of swichable light valve elements for selectively generating a plurality of beams of retroillumination light. 
     
     
       13. The microscopy system according to  claim 1 , wherein the retroillumination system comprises a light source and a plurality of switchable mirror elements for selectively generating a plurality of beams of retroillumination light. 
     
     
       14. The microscopy system according to  claim 1 , wherein a cross section of the beam of retroillumination light is displaceable in a plane disposed in between the objective lens and the object plane. 
     
     
       15. The microscopy system according to  claim 1 , wherein the retroillumination system comprises a displaceable mirror for reflecting the beam of retroillumination light towards the object plane, and an actuator for changing a distance of the mirror from an optical axis of the objective lens. 
     
     
       16. The microscopy system according to  claim 1 , wherein the retroillumination system comprises a displaceable light source for generating the beam of retroillumination light, and an actuator for changing a distance of the light source from an optical axis of the objective lens. 
     
     
       17. The microscopy system according to  claim 1 , further comprising a standard illumination system generating a standard illumination beam for illuminating a region outside of a pupil of the eye under surgery, wherein the standard illumination system comprises a first light forming device configured to shape the standard illumination beam such that substantially no light of the standard illumination beam enters the pupil. 
     
     
       18. The microscopy system according to  claim 1 , wherein the retroillumination system comprises a second light forming device configured to shape the retroillumination beam such that substantially all light of the beam of retroillumination light enters the pupil. 
     
     
       19. The microscopy system according to  claim 1 , further comprising
 a camera for detecting a red reflex image; 
 a display for the displaying the detected red reflex image to a user; and 
 wherein a filter disposed in a beam path between the objective lens and the camera, wherein the filter is transparent substantially only for wavelengths contained in the beam of the retroillumination light. 
 
     
     
       20. The microscopy system of  claim 1 , wherein the angle between the main ray of the beam or retroillumination light and the main ray of the beam of standard illumination light is between 5° and 9°. 
     
     
       21. A microscopy system for eye surgery, the microscopy system comprising:
 an objective lens for imaging an object plane of the objective lens; 
 a retroillumination system for generating a beam of retroillumination light directed towards the object plane from an objective lens side of the object plane; 
 a light sensor for detecting light emerging from the object plane, wherein the light sensor is configured to generate a signal representing a quality of a red reflex generated by the beam of retroillumination light; and 
 a controller for controlling an actuator configured to change a parameter of the retroillumination system in dependence of the signal representing the quality of the red reflex. 
 
     
     
       22. The microscopy system according to  claim 21 , wherein the parameter is an angle between a main ray of the beam of retroillumination light and an optical axis of the objective lens. 
     
     
       23. The microscopy system according to  claim 21 , wherein the parameter is at least one of a convergence and a polarization of the beam of retroillumination light. 
     
     
       24. The microscopy system according to  claim 21 ,
 wherein the retroillumination system comprises a first polarizer for changing a polarization of the beam of retroillumination light. 
 
     
     
       25. The microscopy system according to  claim 21 , wherein the controller is configured to modulate an intensity of the beam of retroillumination light. 
     
     
       26. A microscopy system for eye surgery, the microscopy system comprising:
 an objective lens for imaging an object plane of the objective lens; 
 a retroillumination system for generating a beam of retroillumination light directed towards the object plane from an objective lens side of the object plane, wherein the retroillumination system comprises a collimator for changing at least one of a convergence and a divergence of the beam of retroillumination light; and 
 a controller for controlling an actuator coupled to the collimator. 
 
     
     
       27. A microscopy system for eye surgery, the microscopy system comprising:
 an objective lens for imaging an object plane of the objective lens; 
 a retroillumination system for generating a beam of retroillumination light directed towards the object plane from an objective lens side of the object plane, wherein
 the retroillumination system comprises a collimator for changing at least one of a convergence and a divergence of the beam of retroillumination light; 
 
 a detector for detecting light emerging from the object plane; 
 a first control module configured to generate a contrast signal based on an intensity variation across the object plane of the detected emerging light; and 
 a second control module configured to change the convergence of the beam of retroillumination light in dependence of the generated contrast signal. 
 
     
     
       28. A retroillumination method for an eye of a patient, the method comprising:
 directing a beam of retroillumination light through a pupil of the eye onto a retina of the eye; 
 detecting an image of an object plane disposed in a region of the pupil of the eye; and 
 changing an angle of the directed beam of retroillumination light with respect to the pupil of the eye, based on the detected image. 
 
     
     
       29. A retroillumination method for an eye of a patient, the method comprising:
 directing a beam of retroillumination light through a pupil of the eye onto a retina of the eye; 
 detecting an image of an object plane disposed in a region of the pupil of the eye; and 
 changing at least one of a convergence and a divergence of the beam of retroillumination light based on the detected image. 
 
     
     
       30. A microscopy system for eye surgery, the microscopy system comprising:
 an objective lens for imaging an object plane of the objective lens; 
 a retroillumination system for generating at least one beam of retroillumination light directed towards the object plane from an objective lens side of the object plane, wherein the beam of retroillumination light comprises substantially only visible light having wavelengths greater than 540 nanometers; and 
 a standard illumination system for generating a standard illumination beam directed towards the object plane from the objective lens side of the object plane such that a main ray of the standard illumination beam traverses the object plane under an angle greater than 4° with respect to an optical axis of the objective lens.